The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant bittercress in Winnetka can be figured out by looking at the USDA zone info.

Planting Calendar for Bittercress

Frost tolerance for bittercress:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Bittercress can survive in some cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant bittercress in Winnetka is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant bittercress and expect a good harvest is probably August. Any later than that and your bittercress may not have a chance to really do well. Starting your bittercress indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Winnetka. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Winnetka is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Winnetka it frosts late in the year after April 15 so be sure to be ready to protect your bittercress if you have one of those late frosts.

USDA Zone Info for Winnetka

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Winnetka

You may be interested in your other planting guides for Winnetka.